Power cables are employed in a variety of subterranean applications. For example, power cables are used to supply power to electric submersible pumping systems deployed in wellbores for pumping fluid, such as petroleum or other production fluids. In some wellbore applications, the power cable is subjected to harsh conditions, including high temperatures and high pressures. Over time, the power cable insulation tends to degrade and the degradation eventually causes cable failure, thus limiting the lifetime of the electric submersible pumping system. In many of these applications, the insulation layer of the electric submersible pumping system cable is subjected to severe external conditions as well as severe internal conditions, e.g. high heat generated by the cable conductor. Additionally, the insulation can be subjected to voltage stress and may eventually come into contact with well fluid or gases.